Study of dimming control methods for HID automotive lamps

Abstract

HID lamps offer better efficacy than halogen lamps and hence many cars are being fitted with metal halide HID lamps. The lamps are operated at 35 W in automobiles in all driving conditions. The present paper proposes for the first time the techniques to achieve dimming control by operating the lamp at reduced power to save energy in low-beam driving. The paper investigates the merits of each method and discusses the practical issues for implementing such a control.